Pyrazolo(3,2-c)-s-triazoles and process for the manufacture thereof

ABSTRACT

A PROCESS FOR PRODUCING 1H-PYRAZOLO(3,2-C)-S-TRIAZOLES BY FUSING THE REACTION PRODUCT OF A THIOCARBOHYDRAZIDE AND AN ALKYLHALIDE WITH A KETO-ESTER. THE PRODUCT HAS UTILITY AS A PHOTOGRAPHIC COUPLER COMPOUND FOR PRODUCING MAGENTA DYES AND ALSO AS AN INTERMEDIATE FOR SYNTHESIZING VARIOUS AZAMETHINE DYES, AZO DYES, AND CYANINE-SENSITIZING DYES FOUND USEFUL IN THE PHOTOGRAPHIC ART.

United States Patent 3,705,896 PYRAZOLOB,2-c]-s-TRIAZOLES AND PROCESSFOR THE MANUFACTURE THEREOF Joseph Bailey, Bushey Heath, England,assignor to Eastman Kodak Company, Rochester, N.Y.

No Drawing. Filed Jan. 15, 1971, Ser. No. 106,891 Claims priority,application Great Britain, Jan. 15, 1970, 1,957/ 70 Int. Cl. C09b 23/00;C0741 55/06 US. Cl. 260-240 E 11 Claims ABSTRACT OF THE DISCLOSURE Aprocess for producing 1H-pyrazolo[3,2-c]-s-triazoles by fusing thereaction product of a thiocarbohydrazide and an alkylhalide with aketo-ester. The product has utility as a photographic coupler compoundfor producing magenta dyes and also as an intermediate for synthesizingvarious azamethine dyes, azo dyes, and cyanine-sensitizing dyes founduseful in the photographic art.

This invention relates to an improved process for the synthesis oflH-pyrazolo[3,2-c]-s-triazoles.

British patent specification No. 918,128 describespyrazolino-benzimidazole color photographic couplers which form magentadyes on coupling or reacting with oxidized color developers. However,couplers of this general type sometimes produce inadequate color imageswhen incorporated into silver halide emulsions in the form of adispersion.

Magenta dyes formed from S-pyrazolone couplers, for example, frequentlyexhibit unwanted absorption in the blue-light range and do notdemonstrate a satisfactorily sharp spectral absorption curve on the longwavelength side.

As a result, there has been a long continuing search for new magentadye-forming photographic couplers which will produce dyes having betterspectral absorption characteristics combined with good couplingactivity, plus new and better ways of producing them.

It is an object of the present invention to find a new and more directreaction process for producing various lH-pyrazolo[3,2-c]-s-triazolesfrom the corresponding S- alkyl-isothiocarbohydrazide hydrohalides withketo esters.

The above object is accomplished in accordance with the instantinvention whereby a class of dye-forming photographic couplers isobtained by reacting an isothiocarbohydrazide hydrohalide witha ketoester, the isothiocarbohydrazide reactant being conveniently obtained,for instance, from the corresponding thiocarbohydrazide with an alkyl ora substituted alkyl halide such as the iodide. The preparation ofisocarbohydrazide is more readily controlled if effected in an inertorganic solvent such as a lower aliphatic alcohol, exemplified by amylalcohol.

An aspect of the present invention is conveniently demonstrated by thefollowing equation:

NN R M 215 wherein R is defined as an alkyl, alkylthio, aryl, orheterocyclic radical containing -6 members in the nucleus; suchdefinitions include, for instance, a straight or branched chain alkylmoiety of 1-22 carbon chain, and particularly a tertiary alkyl of 1-8carbon atoms, exemplified by (t)- butyl and 2,2-dimethyl propyl. Thealkyl thio radicals include methyl-, octyland octadecylthio moieties;aryl group includes phenyl, 04- or B-naphthyl radicals; and theheterocyclic radical typically includes radicals having an oxygen,nitrogen, or sulfur atom in the cyclic nucleus as exemplified by furyl,pyridyl, and thienyl radicals. R as defined, also includes theabove-listed radicals such as alkyl, aryl, alkylthio, etc., whichcontain substituent groups attached thereto such as hydroxyl, amino,nitro, halo, and aryl groups, inclusive of chloro, phenyl, naphthyl, andbenzyl groups; X is an acid anion exemplified by halide ions such asCl-, Br-, I-, particularly the iodide ion. R is an alkyl group including1-22 carbon containing alkyls and particularly lower alkyls such asmethyl, ethyl, isopropyl and octyl; and wherein R is defined as SR, inwhich R is an alkyl including substituted alkyl groups, as exemplifiedby methyl, ethyl, octyl, dodecyl, eicosyl, halo alkyl, particularlylower alkyls.

Compounds of interest for purposes of the present invention includethose in which the R radical is defined'as an -SR group and R is definedas a lower alkyl and particularly where R is a branched lower alkylradical.

The above described reaction is conveniently effected by using areactive amount, i.e., a ratio of carbohydrazideto-keto ester of aboutl1.5 :1 at an elevated temperature, preferably at reflux temperatures offrom about C. The cyclization reaction as described above andhereinafter exemplified may be effected without a reaction solvent,however, amyl alcohol can be used for this purpose, if desired.

Substituents required at the #7 coupling position of Compound III can beincluded within the scope of the present invention. By way of example, ahalo substitucnt radical such as a bromine or chlorine atom may beintroduced onto the 7-position of a compound of Formula III to obtain acompound of the formulae: I

(IV) R N 7 \N/ i.

wherein R and R constitute the additional substituent groups. By way ofexample, halo radicals may be introduced by treatment with ahalogenating agent such as bromine or sulfurylchloride in the manner ofExamples 8-9.

The above-indicated halo radicals and many other substituent groups mayalso be introduced into #7 position of Formula III in the mannerdescribed in copending US. patent applications Ser. Nos. 106,892 and106,893 which are continuations-in-part of abandoned Ser. Nos. 778,329and 778,333 entitled Color Forming Couplers and Dyes for Photography,filed Nov. 22, 1968, and in Belgian Pat. No. 724,427, which areincorporated by reference. In accordance with the supplemental stepsdisclosed, R may be here defined to include halo, such as chloro orbromo; cyano; carboxyl; sulfonic acid group; an acyloxy, such as thecorresponding radicals of formic, isovaleric and arachidic acids;aryloxy, such as a phenoXy, or naphthoxy; an arylthio such asphenylthio; an amino radical including substituted amines exemplified byN- methyl amino, N-octyl amino, N,N-di-methyl and N-octadecyl amino;also -N=NR wherein R is the residue of an aromatic or heterocyclicdiazotizable amine precursor. R is also usefully defined to include achromophoric-free development-inhibiting organic radical such asdescribed and prepared, for instance, in British patent specificationNo. 953,454 and U.S. Pat. 3,227,554 and herein incorporated byreference.

If, for example, it is desired to make a compound of Formula IV in whichR is defined as wherein represents a heterocyclic nuclei such as apyrazolotriazole residue, L is a methine or straight chain conjugatedhydrocarbon linking group, and n is -3, two moles of the appropriatecompound of Formula III are reacted with one mole of a compound used inthe preparation of symmetrical cyanine dyes. Examples of Such compoundinclude ethyl ortho-formate (It-=0) and 1,1,3-trimethoxy-3-ethoxypropane (n=1). Generally speaking, if it is desired to obtain acompound of Formula IV or V in which R and R are respectively andwherein and are heterocyclic nuclei of the kind present in cyanine andrelated dyes as further described in our above-cited copendingapplication entitled Dyes for Photography and Belgian Pat. 724,427, andn is O3, then an appropriate compound of Formula IV, in which R ishydrogen, can be reacted with a compound having the desired nucleus andsubstituted with a group which will provide, On reaction, the requiredlinkage. If this linkage is a direct one, an alkoxy or alkylthio groupwill serve. If a single methine group linkage is required, an aldehydeor alkoxymethylene group is used. If a two-carbon methine chain isrequired, an acylanilidovinyl group is utilized; if a three-carbon chainis required an alkoxyallylidene group is used; and if a four-carbonchain is required, an acylanilidobutadienyl group may be utilized.

Also included within the scope of the present invention is the combinedreaction mechanism described above whereby it is possible to obtainproduct compounds of Formula IV wherein the R radical is joined at the#7 coupling position of the coupler molecule by a thio linkage (--S)which is broken during development to yield a dilfusible mercaptocompound functioning as the development-inhibiting substance. Thecoupler product is known as a DIR coupler. In such case R may beconveniently defined as a S phenyl or -S-naphthyl group, or as in whichis defined as a heterocyclic radical containing at least one heteronitrogen, oxygen or sulfur atom, and preferably 1-4 nitrogen atoms.

The coupler compound may contain, for instance, a mercaptotetrazole, athioglycolic acid derivative, a mercaptothiazole, a thiosalicyclic acid,a mercaptoalkylamidobenzothiaozle, a mercaptoalkylamido thiazole, amercaptoazine, a mercaptoazole, a mercaptocysteine, amercaptoglutathione, a mercaptooxadiazole, a mercaptopyrimidine, amercaptothiadiazole, a mercaptothiophene, a mercaptotriazine and amercaptotriazole group in coupling position. The above groups may alsoinclude the substituted groups having, as substituents, nitro, halo(chloro, bromo, etc.), lower alkyl (methyl, octyl), lower alkylamido(methyl and butylamide), lower alkoxy of 1-8 carbon atoms, loweralkylsulfonamido, a-chloroacetylthio, amino, and lower alkyl carbamyl.

Corresponding suitable development-inhibiting moieties of the abovecoupler compounds, which are liberated during development of thephotographic emulsions with primary aromatic amino silver halidedeveloping agents, include, for instance, triazolyl, tetrazolyl,thiazolyl and mercaptotetrazolyl radicals. Displaceable groups as abovelisted may also be conveniently linked to the coupler residue in thecoupling position by azo linkages; o-amino and oamido monocyclic aryl(i.e., phenyl or naphthyl) azo radicals, azoxy and triazolyloxyradicals.

R is further conveniently defined as a substituent radical of theformula wherein L is a methine or straight chain conjugated hydrocarbonlinking group, particularly (CH=CH) --CH= in which n is O-3; and

represents a heterocyclic moiety, particularly of the kind present incyanine or cyanine-type related dyes to complete the chromophoricsystem. Such heterocyclic radicals include, for instance, a residue ofthe Formula V supra in which L, as above defined, replaces the Rradical.

Included within the definition of R are heterocyclic groups inclusive ofa pyrazolo-s-triazolylidene, a thiothiazolidone, a4,6-dioxo-hexahydrothiopyrimidylidene, a 2-pyrrole, a S-pyrrole, aZ-indole, a 3-indole, a l-indolizine, a 3-indolizine, a rhodanine, or abarbituric acid group.

The R radical of Formula V is conveniently defined as R plus a proton,where Formulae IV and V represent tautomers; as a cyclic radical orgroup completing the chromophoric system of a cyanine or cyanine-typedye; as an aryl radical such as a benzylidene radical, includingnitrobenzylidene; R is also conveniently defined as a radical of theformula in which L and n are defined as above for R and represents aheterocyclic radical. Heterocyclic radicals of the present invention indefining R include triazole, indolenine, benzthiazole, pyrrole,benzoxazole, benzoselenazole, benzimidazole, quinoline, and isoquinolineradical groups.

The above compounds of Formulae IV and V, in which R and R are groupscompleting a chromophoric system, are dyes which are generally suitablefor use as sensitizing dyes for photographic silver halide emulsions orfilter dyes.

The compounds of Formula IV, in which R is a group which splits off ontreating the compound with an oxidized colour developing agent may beemployed as dye-forming couplers in colour photographic processes. Thus,depending upon the other substituents present in the molecule, thedefined compound can be incorporated in a colour developing solution fora silver halide emulsion layer, or in a silver halide emulsion layerwhich is to be developed in a colour developing solution which containsno dye-forming coupler. In either case the colour developing agent canbe one of the well-known primary aromatic amine develop ing agents suchas:

N,N-diethyl-p-phenylenediamine monohydrochloride,N-methyl-p-phenylenediamine hydrochloride,N,N-dimethyl-p-phenylenediamine hydrochloride,2-amino-5-diethylaminotoluene monohydrochloride, 2-amino-5-(N-ethyl-N-lauryl) toluene,N-ethyl-N-fi-methanesulphonamidoethyl-3-methyl-4- amino-anilinesesquisulphate monohydrate,N-ethyl-N-fi-methanesulphonamidoethyl-4-aminoaniline,4-N-ethyl-N-B-hydroxyethylaminoaniline,4-amino-3-methyl-N-ethyl-N-p-hydroxyetbyl aniline sulphate; and4-amino-N,N-diethyl-3-/3-methanesulphonamidoethyl aniline hydrochloride.

The dye obtained upon reaction of coupler in solution with the oxidizedcolor developing agent will be an azamethine dye and can be used as afilter dye.

The following examples illustrate the invention:

EXAMPLE 1 3-methylthio-6-phenyl-1H-pyrazolo [3 ,2-c1-s-triazole(Compound 1) Ethyl benzoylacetate (9.6 grams) and S-rnethylisothiocarbohydrazide hydriodide (12.4 grams) were heated together at110-115 C. for 25 minutes. During the last 5 minutes of the heating thevolatile reactants were distilled otf in vacuo. The reaction mixture wascooled and then heated with sufficient boiling sodium carbonate solution(about 300 ml.) to effect solution of most of the reaction mass. A smallamount of oily residue remained which was removed by filtration. Oncooling the hot clear carbonate solution the product crystallized andwas collected by filtration. It was recrystallized from benzene as tinybuff-coloured needles. The yield of product which melted at 179 C. was 5grams. It coupled with oxidized 2-amino-S-diethylaminotoluene developerto give a dye which had I ethyl acetate at 565 nm. The S-methylisothiocarbohydrazide hydriodide was prepared by adding methyl iodide(18 grams) to a well stirred suspension of thiocarbohydrazide (12 grams)in boiling ethanol (400 ml.) and heating under reflux for 2 hours. Theproduct was isolated by cooling the hot filtered solution and collectionof the separated product by filtration. Concentration of the ethanolsolution to about half volume gave a second crop. The yield ofcolourless crystals was 70%. The product melted at 145 (withdecomposition).

EXAMPLE 2 3-methylthio-6-m'-nitrophenyl-lH-pyrazolo[3,2-c]-striazole(Compound 2) 4IUITSCH3 Ethyl m-nitrobenzoyl acetate (2.4 grams andS-methyl isothiocarbohydrazide hydriodide (2.5 grams) were heated at 120C. for 15 minutes. The reaction mass was treated a with carbonatesolution as described in the previous ex- EXAMPLE 36-heptadecyl-3-methylthio-lH-pyrazolo[3,2-c]-striazole (Compound 3) NNHSCHs M N C17H35 H A solution of ethyl stearoylacetate (2.1 grams) andS- methyl isothiocarbohydrazide hydriodide (1.6- grams) in n-amylalcohol (25 ml.) was heated under reflux for 2 hours. On cooling somesolid material separated and was collected by filtration. Ether wasadded to the amyl alcohol solution to precipitate more solid materialwhich was also filtered off. Neither solid coupled with oxidizeddevelopers. The solution Was concentrated to leave an oil which wastreated with benzene ml.) and the solvent again removed. The residualgum (2 grams) coupled with oxidized Z-amino-S-diethylamino toluenedeveloper to give a dye having k ethyl acetate at 541 nm.

EXAMPLE 4 3 -methy1thio-fi-p-nitrophenyl-lH-pyrazolo [3,2-c] s-triazole(Compound 4) Ethyl p-nitrobenzoylacetate (2.26 grams) andS-methylisothiocarbohydrazide hydriodide (2.36 grams) were heated inboiling amyl alcohol (40 cc.) for 35 minutes. The reaction mixture wascooled and the product which precipitated as yellow crystals wascollected by filtration and recrystallised from amyl alcohol. Thepurified product was collected, washed with ethanol and dried. The yieldof product which melted at 277 C. was 1 gram. It coupled with oxidizedZ-amino-S-diethylaminotoluene developer to give a dye with A ethylacetate at 588 nm.

EXAMPLE 5 3-methylthio-6-pr0pyl-lH-pyrazolo 3,2-c] -striazole (Compound5) Cam- N/ This compound was prepared similarly to Example 3 using aproportionate amount of ethyl butyrylacetate instead of ethylstearoylacetate. The product which was obtained as a gum coupled withoxidized 2-arnino-5-diethylaminotoluene developer to give a dye with xethyl acetate at 541 nm.

7 EXAMPLE 6 6,2'-fury1-3-methylthio-1H-pyrazolo[3,2-c]-s triazole(Compound 6) N-N- S0113 i it This compound was prepared as in Example 3using ethyl- Z-furoylacetate instead of ethyl stearoylacetate. Theprodnot which was obtained as a guru coupled with oxidized2-amino-S-diethylaminotoluene developer to give a dye having 71 ethylacetate at 67 nm.

EXAMPLE 7 3,6-di(methylthio)-1H-pyrazolo[3,2-c] s-triazole (Compound 7)O-ethyl S methyl asymmetric diethiomalonate (1.78 grams) (Laakso, SuomenKemistilehte, 1944, 1713, 1-6) and S-methyl isothiocarbohydrazidehydriodide (2.36 .grams) were heated in boiling amyl alcohol (25 ml.)for 30 minutes and worked up as in Example 3. The product which wasobtained as a gum coupled with oxidized 2- amino-S-diethylamiuo toluenedeveloper to give a dye having k ethyl acetate at 5 33 nm.

EXAMPLE 8 7-bromo-3-methylthio-6-phenyl-lH-pyrazolo- [3,2-c1-s-triazole(Compound 8) I Br EXAMPLE 9 7-chloro-3 -methylthio 6-phenyl-IH-pyrazolo-[3,2-c]-s-triazole (Compound 9') UL-IFS C Ha can. i

Compound 1 (1 gram) was dissolved in acetic acid ml.) and sulphnrylchloride (0.65 gram) were slowly added to the solution, the mixture washeated on the steam bath for 5 minutes and allowed to stand at roomtemperature for 1 hour. The mixture was then poured into water (200 ml.)and the precipitated product was collected by filtration and dried. Itweighed 0.9 gram and melted at 150 8 EXAMPLE 1o 7 (3 methylthio 6 phenyl7H pyrazolo[3,2-c]- s triazol 7 ylidene) methylene 3 methylthicrG-phenyl-lH-pyrazolo[3,2-c]-s-triazole (Compound 10) Compound 1 (0.1gram), ethylorthoforrnate (1 ml.) and acetic acid (4 ml.) were heated atboiling point for 5 minutes. The product which crystallized from the hotreaction mixture was isolated after cooling by filtration. It was washedwith ethanol, dried and obtained in almost theoretical amount. It has anabsorption maximum in methanol in the presence of triethylamine at 494nm.

EXAMPLE 11 7,3 (3 methylthio 6 phenyl 7H pyrazolo[3,2-c]- s triazol 7ylidene)allylideue 3 methylthio 6-phenyl-ll-l-pyrazolo[3,2-c]-s-triazole (Compound 11) A solution ofCompound 1 (0.23 gram) and 1,1,3-trimethoxy-3-ethoxypropane (0.2 ml.) inacetic acid (5 ml.) was heated under reflux for 2 minutes. The solid dyeprod uct separated from solution and after cooling it was collected andrecrystallized in almost quantitative yield from methanol. The productwas obtained as dark green metallic crystals 1 methanol at 554 nm.

EXAMPLE 12 3-ethyl-2- 3-methylthi0- 6-phenyl-7H-pyrazolo [3 ,2-c]-striazole-7-ylidene)benzthiazoline (Compound 12) Compound 1 (0.23gram), 2-ethylthiobenzthiazole ethiodide (0.34 gram), triethylamine (0.5ml.) and ethanol (5 ml.) were heated under reflux for 10 ruins. Afterchilling the reaction mixture, the separated dye was collected andrecrystallised from ethanol as pale yellow crystals. It weighed 0.1 gramand had A methanol at 410 nm.

EXAMPLE 13 3-methylthio-7-p-nitr0benzylidene-6-phenyl-7H-pyrazol0[3,2-c]-s-triazole (Compound 13) Compound 1 (0.23 gram), p-nitrobenzaldehydeand acetic acid (5 ml.) were heated under reflux for 10 mins. Aftercooling the product was precipitated by dilution with water (25 ml.)and. collected by filtration.

It was twice recrystallised from ethanol and obtained in 20% as paleyellow crystals. It coupled with oxidized 2-amino-5-diethylamino toluenedeveloper to give a dye k ethyl acetate at 565 nm.

EXAMPLE 14 7-(l-ethyl-2,5 dimethyl-3pyrryl)methylene-3-methylene-3-metlrylthio-6-phenyl 7H-pyrazolo[3,2.-c]-s-triazole (Compound 14) TOE I l CHaUCH; ll N N CHaSN Compound 1 (0.46 gram), 1-ethyl-2,S-dimethylpyrrol- 3-aldehyde (0.3gram) were dissolved in boiling ethanol ml.) and triethylamine (1 ml.)was added and the solution was reflux for 10 minutes. The solution wasconcentrated to 5 ml. and well chilled when the dye product (0.25 gram)separated. It was twice recrystallised from methanol givin 0.15 gramorange needles. The dye has A methanol at 447 nm.

EXAMPLE 5-(3-methylthio 6 phenyl1H-pyrazolo[3,2-c]-s-triazol-7-yl)methylene 3phenyl-2-thiothiazolid-4-one (Compound 15) EXAMPLE 16 3-ethyl-2,2' (3methylthio-6-phenyl-1H-pyrazolo[3,2-

c]-s triazole 7 ylidene)ethylidenebenzoxazoline (Compound 16) A mixtureof Compound 1 (0.23 gram) 2,2'-acetanilidovinylbenzoxazole ethiodide(0.45 gram), triethylamine (0.42 ml.) and ethanol (20 ml.) was heatedunder reflux for 10 minutes. Water (20 ml.) was added to the cooledreaction solution and the product which was obtained in almostquantitative yield was recrystallised from methanol as yellow crystalshaving x methanol at 480 nm.

10 EXAMPLE 17 3-ethyl-2,2' (3-methylthio-6-phenyl 7H-pyrazolo[3,2-c]-s-triazol-7-ylidene)ethylidenebenzthiazoline (Compound 17) CH S I472115 Compound 1 (0.46 gram) 2,2-acetanilidovinylbenzthiazole ethiodide(0.9 gram), triethylamine (1 ml.) and ethanol (30 ml.) were heatedtogether on a steam bath for 10 minutes. The reaction mixture was cooledand the separated product was collected by filtration. It wasrecrystallised twice from methanol. The purified product Weighed 0.2gram and has A methanol at 521 nm.

EXAMPLE 18 7,3-(l,3 diethyl 4,6-dioxo-hexahydro-2-thi0pyrimid-5-ylidene)allylideue 3 methylthio-6-phenyl-lH-pyrazolo[3,2-c]-s-triazole(Compound 18) CoHs 0 H5 I ll;

Compound 1 (0.46 gram) and 1,3-diethyl-4,6-dioxo-5-(3-ethoxyallylidene)hexahydro 2-thiopyrirnidine (0.56 gram) weredissolved in boiling ethanol (20 ml.) and the mixture was refluxed for10 minutes. The reaction mixture was cooled and the dye was collected byfiltration. The product was purified by dissolving it in hot pyridineand reprecipi-tating by the addition of ethanol to the cooled pyridinesoltion. The product which weighed 0.4 gram had A methanol at 535 nm..and 561 nm.

EXAMPLE l9 3-ethyl-2,4-(3-methylthio 6 phenyl-7H-pyrazolo[3,2-

c]-s-triazol-7-ylidene) but 2' enylidenebenzthiazoline (Compound 19)Compound 1 (0.46 gram), 2,4-acetanilidobutadienylbenzthiazole ethiodide(0.95 gram)'were dissolved in boiling ethanol (70 ml.). Triethylamine (1ml.) was added and a deep blue dye was formed. The mixture was heatedunder reflux for 5 minutes and on chilling dark blue needles separated.The product (0.6 gram) was collected and recrystallised twice frommethanol. The dye had A methanol at 619 nm.

EXAMPLE 20 A sensitizing amount of each of dye Compounds 11, l6, l5, 17,12 and 19 indicated in the table below was added to separate portions ofa negative-type, developing out gelatino silver chlorobromide emulsion.Each of these emulsions was coated onto a piece of cellulose ester filmsupport and dried. Spectrographic exposures were made at second on eachcoating and these were developed 1 1 at room temperature in photographicdeveloper having the following composition:

Water to make 1 litre.

(1) Dye pro- (tl) Dye sen duces max. sltlzes emulsensitlvity sion at-Compouud N o.

EXAMPLE 21 6 heptadecyl 3 methylthio 1H pyrazolo{3,2 c]- s-triazole (0.2gram) was dissolved in dibutyl phthalate (0.4 ml.) at 80 C. A hotsolution (80 C.) of 10% inert bone gelatin (12.8 ml.) and 5%tri-isopropylnaphthalene sulphonate (1.2 ml.) were added to the couplersolution and the mixture was homogenized using an ultrasonic probe.Water (8.8 ml.) and 7.5% solution of saponin (-0.9 ml.) were added andthe mixture was filtered. A gelatino bromo-iodide emulsion (6.8 gramscontaining 0.69 gram silver) was added to the filtrate and the mixturewas coated on a cellulose acetate film base at 425 mg. gelatin/sq. ft.dry weight and the light-sensitive material so obtained was exposed andthen developed for minutes at 20 C. in a color developer of thefollowing composition:

The development was followed by acid stop-fix, ferricyanide bleach andfinally fixation stages when a magenta image was formed in the exposedregions by the formation of a dye having an absorption maximum at 559nm. Other developing agents can be used for example, 3-methyl-4-amino-N-fi-methylsulphonamidoethyl N ethylaniline gives a dyewith absorption maximum at 555 nm.

EXAMPLE 22 A colour developer solution having the formula:

Grams Sodium sulphite 2 2-amin0-5-diethylamino toluene hydrochloride 2Sodium carbonate 20 Potassium bromide 2 Compound 5 (in ethanolsufiicient to dissolve coupler) Water to 1 litre.

pH adjusted to 11.5 with sodium hydroxide solution was used to colourdevelop a magenta image in a strip of image exposed film coated with alayer of silver halide emulsion. The silver in the strip was convertedto silver halide by treating it was a ferricyanidebromide bleach andthen the silver halide was removed by treating the strip with a hypo fixbath to leave a magenta dye image having an absorption maximum at 557nm. A magenta dye image having an absorption maximum at 570- nm. wasobtained when 3-rnethylthio-6-phenyl-1H-pyrazolo[3,2-c]- s-triazole(Compound 1) is used as the coupler and N,N- diethyl-p-phenylenediamineas the developing agent in the above formula.

EXAMPLE 23 3-ethylthio-6-phenyl-ll-I-pyrazolo[3,2-c]-s-triazole NN-S02H:

t B I N/ Ethyl benzoylacetate (4.8 g.) and S-ethyl isothiocarbohydrazidehydroiodide (6.5 g.) were heated together at -115 for twenty minutes,and then for a further dive minutes while the volatile reactants weredistilled off in vacuo. The reaction mass was cooled and treated withboiling 10% sodium carbonate solution (150 ml.) when most of thereaction product dissolved. The solution was filtered, chilled to givethe product which was collected by filtration and recrystallised frombenzene. The product, M.P. 142", was obtained in 23% yield and coupledwith oxidised 2-amino-5-diethylaminotoluene developer to give a dyewhich had A in ethyl acetate at 564 nm.

S-ethyl isothiocarbohydrazide hydriodide was prepared fromthiocarbohydrazide and ethyliodide similarly to the preparation ofSFmethyl isothiocarbohydrazide hydriodide (see Example 1) but theheating period was extended to six hours. The yield of product, M.P. 145was 35%.

EXAMPLE 24 G-tertiary butyl-3-ethylthiolH-pyrazolo[ 3,2-c] S-triazoleCsHs This was prepared similarly to Example 1 usingS-benzylthiocarbohydrazide hydriodide (obtained in 10% yield fromthiocarbohydrazide and benzyl iodide in boiling ethanol for two hours)instead of S-methyl isothiocarbohydrazide hydriodide. The productcoupled with oxidized Z-amino-S-diethylaminotoluene developer to give adye having A in ethyl acetate at 562 nm.

The invention has been described in considerable detail with particularreference to certain preferred embodiments thereof, but it will beunderstood that variations and modifications can be eifected within thespirit and scope of the invention.

(I claim:

1. A process for producing a pyrazolo[3,2-c] -s-triazole comprisingcontacting a reactive amount of an isothiocarbohydrazide of the formulaR1 i 2N mg 2. The process of claim 1 wherein reactive amounts of theisothiocarbohydrazide and keto ester are contacted at a temperature ofabout 75 130 C.

3. A process for producing cyanine dyes comprising contacting a reactiveamount of an isothiocarbohydrazide of the formula with a keto ester ofthe formula R -COOCH COOR" to obtain the cyclized intermediate of theformula R is defined as -SR wherein R is an alkyl group;

R is an alkyl group;

R is an alkyl, alkylthio, phenyl, naphthyl, furyl, pyridyl or thienylradicals; and

X is an acid anion;

and contacting said cyclized intermediate with a reactant selected fromthe group consisting of an alkyl ester of a lower aliphatic acid, apolyalkoxy lower alkane, and

wherein R is defined as an alkoxy, alkoxythio, HCO,

14 alkoxy lower alkyl, acylanilidovinyl, alkoxyalkylidene, oracylanilidobutadienyl group, and

is a triazole, indolenine, benzthiazole, pyrrole, benzoxozole,benzoselenazole, benzimidozole, quinoline or isoquinoline groupcharacteristic of cyanine and related dyes. 4. The process of claim 1wherein R is an alkyl and R is an alkylthio radical.

5. The process of claim 1 wherein R is an alkylthio and R is analkylthio radical.

6. The process of claim 1 wherein R is a tertiary alkyl and R is a loweralkylthio radical.

7. The process of claim 1 wherein X is an iodide anion.

8. The process of claim 1 wherein the molar ratio ofisothiocarbohydrazide-to-keto ester is about 1:1.

9. The process of claim 3 wherein the reaction of the cyclizedintermediate is effected in the presence of an inert organic reactionsolvent.

10. The process of claim 9 wherein the reaction is eflfected with alower alkanol or lower alkanoic acid as a reaction solvent.

11. A process for producing a pyrazolo[3,2-c]-s-triazole comprisingcontacting 1) S-methyl isothiocarbohydrazide hydroiodide with a reactiveamount of (2) ethyl benzoylacetate, ethyl m-nitrobenzoyl acetate, ethylstearoylacetate, ethyl p-nitrobenzoylacetate, ethyl butyrylacetate,ethyl-2-furoylacetate, or O-ethyl-S-methyl asymmetric diethiomalonate;affecting the reaction at a temperature of about 130 C. and molar ratioof about 1:1, and recovering the resulting cyclized product.

References Cited Beyer et al., Chem. Ber. vol. 89, pp. 2550-2555 (1956).Reimlinger et al., Chem. Ber. vol. 103, pp. 3284-3288 1970) JOHN D.RANDOLPH, Primary Examiner U.S. Cl. X.R.

96-130, 136; 260-2404, 240.5, 240.65, 240.7, 240.9, 294.8 C; 306.8 F,308 R

